The surface water system in the North Creek Basin has undergone significant alteration over the past century. The 1847 General Land Office Survey shows North Creek extending from Little Sarasota Bay, east across the approximately 2½-mile-wide basin to what appears to be a pond. The 1959 USDA NRCS Soil Survey shows two north-south ditches leading to North Creek. The ditch to the south leads to an area in the west that appears to be a development. With the exception of the western boundary, U.S. 41, and some ditches, the basin was still fairly undeveloped by the 1970s. By 2000, roughly half of the basin was developed and about 1,930 people resided in the developed areas (U.S. Census Bureau, 2000). Today, about 75% of the basin is developed and laden with ditches and stormwater infrastructure, with half of the development residential. For basin details see: Little Sarasota Bay Water Quality Management Plan (2012)

Water Chemistry Ratings - Freshwater Portion of the Creek

Total nitrogen, total phosphorus, chlorophyll a, and dissolved oxygen levels are monitored carefully
by water resource managers and used by regulatory authorities to determine whether a creek meets the water
quality standards mandated by the Clean Water Act. Shown below are water quality data for each freshwater stream
segment. Florida law defines a threshold for the maximum allowable concentration of nitrogen, phosphorus,
and chlorophyll a, and the minimum required concentration of dissolved oxygen in these streams. Learn more about these ratings and how they are calculated »

Data for the following WBIDs is averaged when compiling the data below:

Five-year Trend Graph

Chlorophyll a

The rating for Total Phosphorus is determined by comparing the annual geometric mean of its sampled values to fixed target and threshold values. The geometric mean is found by multiplying together all the sample values for the calendar year and then taking the nth root of the result, where n is the number of samples. The annual geometric mean for Total Phosphorus is shown in the graph at left, as compared to its established target and threshold values.

Five-year Trend Graph

Other Measures of Creek Health

Water Chemistry Ratings - Tidal Portion of the Creek

As is the case for predominantly freshwater streams, total nitrogen, total phosphorus, and chlorophyll a levels are monitored
carefully by water resource managers and used by regulatory authorities to determine whether a tidally-influenced stream meets the water
quality standards mandated by the Clean Water Act. Shown below are water quality data for each saltwater water body within this basin.
Florida law defines a threshold for the maximum allowable concentration of chlorophyll a
and the minimum required concentration of
dissolved oxygen in these streams. No thresholds have been established for the allowable concentration of nitrogen or phosphorus;
trend information is provided for these nutrients, to determine whether a statistically significant trend exists and if so, whether
levels are rising (bad) or falling (good). Learn more about these ratings and how they are calculated »

Data for the following WBIDs is averaged when compiling the data below:

Chlorophyll a

The rating for Chlorophyll a is determined by comparing the annual arithmetic mean of its sampled values to fixed target and threshold values. The annual arithmetic mean is shown in the graph at left, as compared to its established target and threshold values.

Other Measures of Creek Health

Oysters

Because they are immobile and will tolerate a fairly wide salinity range, eastern oysters (Crassotrea virginica) are valuable as an indicator of the relative health of aquatic ecosystems in the tidally-influenced portions of coastal creeks. Sarasota County has established an oyster monitoring program to track the location, types, and status of oyster reefs. Data from this monitoring program is shown below.
Learn more about Oysters »

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Most Recent Sarasota County Oyster Monitoring Program Data

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Site ID

Year

Latitude_DD

Longitude_DD

Dead

Live

Total

% Live

1

NO1

2015

27.21638

-82.498721

98

560

658

85

Impervious Features

Rain that falls on land that is in a natural state is absorbed and filtered by soils and vegetation as it makes it way into underground aquifers. However, in developed areas, "impervious surfaces" impede this process and contribute to polluted urban runoff entering surface waters. These surfaces include human infrastructure like roads, sidewalks, driveways and parking lots that are covered by impenetrable materials such as asphalt, concrete, brick and stone, as well as buildings and other permanent structures. Soils that have been disturbed and compacted by urban development are often impervious as well.
Learn more about Impervious Features »

Land Use / Land Cover

Land use within a creek's watershed has a major effect on its water quality. In general, less development means better water quality.
Land Cover/Land Use classifications categorize land in terms of its observed physical surface characteristics (e.g. upland or wetland),
and also reflect the types of activity that are taking place on it (agriculture, urban/built-up, utilities, etc.). Florida uses as its
standard a set of statewide classifications which were developed by the Florida Department of Transportation.
Learn more about Land Use and Land Cover »

Year

LULC Category

Area (acres)

Percent

2011

Urban & Built-up

1698.943788

1698.943788

2011

Wetlands

190.774495

190.774495

2011

Water

177.236995

177.236995

2011

Upland Forests

140.992225

140.992225

2011

Rangeland

74.299878

74.299878

2011

Transportation and Utilities

40.080592

40.080592

2011

Agriculture

3.519669

3.519669

2011

Barren Land

0.710090

0.710090

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Data Sources

The data sources listed below provided water quality data used to create the report on this page. Not all data sources provided data for every creek, and not every Creek Conditions Report used data from all listed data sources. While some data sources have no data for the scored year, they provided period-of-record (historical high, mean, low) data. Click on a data source name to review its metadata.